Switched vs Dedicated Telephone Services
Switched Services:
- Switched calls are dialable (users dial a telephone number to make a connection.
- People can reach anyone on public network by dialing a telephone numbers.
- Charges are based on amount of time calls connected.
- Can be used for voice/data/video/ image traffic.
- Can be used with analog and digital telephone lines.
- When callers hang up, network line and equipment are free to be used by another person or data device.
Dedicated Services (Private Lines)
- Organizations use them to save money when they need to transmit large amounts of data or place hours of voice calls to particular places
- Systems have fixed configurations.
- Devices and users can only reach each other.
- Can be used for voice/data/video/ image traffic.
- Can be used with analog and digital telephone lines.
- Users pay a flat monthly fee with no charges per minute used.
Types of Public Switched Networks reference
Message Switching: reference
A process in which complete messages are sent from end to the other. It is not a interactive process, like circuit or packet switching. The complete message is received in one block, stored in one central place and then sent in one clump to the other end.
Circuit Switching: reference
A process of setting up and keeping a circuit open between two of more users so that users have exclusive and full use of the circuit until the connection is released.
- Temporary dedicated connection.
- Ideal for telephone connections.
- Circuit is set up at beginning of call and terminated at end of call.
Packet Switching: reference
A data switching technique. Data conversation is sent in packets. Each packet can be sent along different tracks as they are open and are assembled at the final switching office before they reach distant user - no circuit is left open on a dedicated basis. "Virtua circuit switched" or datagram connections possible.
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